GIP2, a Putative Transcription Factor That Regulates the Aurofusarin Biosynthetic Gene Cluster in Gibberella zeae

• Published in: Applied and Environmental Microbiology Vol. 72; no. 2; pp. 1645 - 1652
• Main Authors: Kim, Jung-Eun, Jin, Jianming, Kim, Hun, Kim, Jin-Cheol, Yun, Sung-Hwan, Lee, Yin-Won
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.02.2006
• Subjects: Amino acids; Base Sequence; Biological and medical sciences; biosynthesis; Daucus; DNA, Fungal - genetics; DNA-binding domains; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; Fusarium graminearum; Gene Deletion; Gene expression; Gene Expression Regulation, Fungal; genes; Genes, Fungal; Genetic Complementation Test; Gibberella - genetics; Gibberella - metabolism; Gibberella zeae; GIP2 gene; messenger RNA; Microbiology; Multigene Family; Mycology; mycotoxins; Mycotoxins - genetics; naphthoquinones; Naphthoquinones - metabolism; Oryza sativa; Pathogens; pigments; Proteins; transcription (genetics); transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Triticum aestivum; Zea mays; Fungi; Gene cluster; Regulation(control); Plant pathogen; Gibberella zeae; Ascomycetes; Biosynthesis; Transcription factor; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.72.2.1645-1652.2006

Gibberella zeae (anamorph: Fusarium graminearum) is an important pathogen of maize, wheat, and rice. Colonies of G. zeae produce yellow-to-tan mycelia with the white-to-carmine red margins. In this study, we focused on nine putative open reading frames (ORFs) closely linked to PKS12 and GIP1, which are required for aurofusarin biosynthesis in G. zeae. Among them is an ORF designated GIP2 (for Gibberella zeae pigment gene 2), which encodes a putative protein of 398 amino acids that carries a Zn(II)₂Cys₆ binuclear cluster DNA-binding domain commonly found in transcription factors of yeasts and filamentous fungi. Targeted gene deletion and complementation analyses confirmed that GIP2 is required for aurofusarin biosynthesis. Expression of GIP2 in carrot medium correlated with aurofusarin production by G. zeae and was restricted to vegetative mycelia. Inactivation of the 10 contiguous genes in the [Delta]GIP2 strain delineates an aurofusarin biosynthetic gene cluster. Overexpression of GIP2 in both the [Delta]GIP2 and the wild-type strains increases aurofusarin production and reduces mycelial growth. Thus, GIP2 is a putative positive regulator of the aurofusarin biosynthetic gene cluster, and aurofusarin production is negatively correlated with vegetative growth by G. zeae.